The invention relates to ground fault current sensing and interrupting devices wherein the circuit current is directed through a primary winding of a neutral excitation current transformer to determine the existence of a ground fault. A differential current transformer employs a pair of conductors extending through the transformer armature to sense the difference in current passing and returning through the circuit. A difference in current thereby indicating a line to ground fault within the protected circuit.
Electronic signal processing circuits are available for determining the presence of a ground fault within a protected circuit and providing a control signal to open the circuit contacts upon such an occurrence. U.S. Pat. No. 4,115,829 entitled "Overcurrent and Ground Fault Responsive Trip Unit For Circuit Breakers" in the name of E. K. Howell describes the electronic circuit within the signal processor.
U.S. Pat. No. 4,348,708 entitled "Ground Fault Circuit Interrupting Device With Improved Coordination of Electronic Circuit Operation" also in the name of E. K. Howell describes the detailed electronics required for determining such ground fault occurrence and for providing such an output signal to interrupt the circuit contacts.
One efficient means for providing a current path through concentric current transformers is described within U.S. patent application Ser. No. 579,337 filed Feb. 13, 1984 an entitled "Magnetic Sensor Module For A Ground Fault Circuit Interrupter", in the names of R. A. Morris et al. This application discloses cylindrical electrically conductive elements joined together in a pressfit relation to conduct current through the transformer apertures in parallel electrically-isolated paths.
The purpose of the instant invention is to provide a current transformer employing integral means for transporting circuit current through a current transformer aperture and having capability for electrical connection to a printed wire board without requiring additional wiring connections.